Straight-Leg Crossed-Arm Sit-Up
Strengthen your core with Straight-Leg Crossed-Arm Sit-Ups! A challenging variation for a tighter midsection.
The Straight-Leg Crossed-Arm Sit-Up is a compound exercise that mainly works the core, with help from the lower back. No equipment needed: it uses just your bodyweight.
Optional Equipment

Straight-Leg Crossed-Arm Sit-Up Muscles Worked
Primary
Abdominals (rectus abdominis); Obliques
Secondary
Deep Core (transverse abdominis); Spinal Erectors (erector spinae)
Straight-Leg Crossed-Arm Sit-Up Variations and Alternatives
How to do the Straight-Leg Crossed-Arm Sit-Up
Starting Position:
Lie flat on your back on a comfortable exercise mat or a flat surface.
Extend your legs straight out in front of you, keeping them close together and fully extended.
Cross your arms over your chest or place your hands on your shoulders, maintaining a comfortable position.
Engaging Core:
Tighten your abdominal muscles by pulling your belly button towards your spine. This is crucial for stability during the movement.
Movement:
Begin the sit-up by lifting your upper body off the ground. Use your abdominal muscles to help lift yourself, keeping your legs straight and pressed against the mat.
As you rise, your torso should move towards your thighs. Aim to sit up to a 45-degree angle or as high as comfortable without straining your back.
Return to Start:
Slowly lower your upper body back down to the starting position, ensuring you maintain control throughout the movement.
Keep your core engaged and avoid arching your back as you return to the mat.
Repetitions:
Perform 10-15 repetitions, resting as needed between sets.
Focus on controlled movements rather than speed, ensuring that you are working your core muscles effectively.
Tips for Beginners:
If you find it difficult to complete the sit-up with straight legs, you can modify by slightly bending your knees.
Keep your movements smooth and avoid using momentum to lift your body; the focus should be on your abdominal muscles.
Breathe out as you lift up and inhale as you lower back down.
Safety:
If you experience any pain in your back or discomfort, stop the exercise and consider consulting with a fitness professional or trainer.
Always ensure that your back remains neutral and avoid pulling on your neck.
Straight-Leg Crossed-Arm Sit-Up FAQs
What muscles does the Straight-Leg Crossed-Arm Sit-Up work?
The Straight-Leg Crossed-Arm Sit-Up mainly works the core, with help from the lower back. The main muscles are the rectus abdominis and obliques.
What equipment do you need for the Straight-Leg Crossed-Arm Sit-Up?
None. The Straight-Leg Crossed-Arm Sit-Up is a bodyweight exercise, so you can do it anywhere.
Is the Straight-Leg Crossed-Arm Sit-Up a compound exercise?
Yes. It's a compound movement, meaning it trains several muscle groups at once rather than isolating one.
What are some Straight-Leg Crossed-Arm Sit-Up variations and alternatives?
Similar exercises include the Three-Quarter Sit-Up, Ab Mat Sit-Up, Arms-Up Full Sit-Up and Assisted Sit-Up.
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